Piano construction



Oct. 23, 1945. w, BETHUNE 2,387,491

PIANO- CONSTRUCTION Filed 001:. 11, 1943 FIG.2.

INVENTOR. JOHN w. BETHUNE ATTORNEYS Patented Oct. 23, 1945 UNITED STATES PATENT OFFICE PIANO CONSTRUCTION John W. Bethune, Wyandotte, Mich.

Application October 11, 1943, Serial No. 505,761

6 Claims.

The present invention relates to piano construction and has among its objects the improvement of pianos both in tone and appearance,

Another object is a cOnstruction which may be used in the manufacture of pianos or may be applied to existing instruments to modify their appearance and greatly improve their tone both in quality and volume.

Other objects will readily appear to those skilled in the art upon reference to the following description and drawing in which:

Figure 1 is a perspective view of a portion of a piano embodying the invention, parts being broken away to show the construction.

Figure 2 is a view in elevation of the rear of an auxiliary sounding board as used therein.

Figure 3 is a view in elevation of the front of the latter.

Figure 4 is a view of a part of the front of the piano frame showing the pressure bars and indicating the pins to which the strings are attached.

Figure 5 is a vertical sectional view of the auxiliary sounding board assembl showing its relation to the pressure bar and pin block.

Referring to the drawing, Figure 1 is a perspective view of a portion of a piano and the outside casing l0, with the usual shelf H for the keyboard (not shown). It should be understood that the interior construction, including the frame across which the strings are stretched, and the usual sounding board, is conventional. This also includes the keyboard and hammer mechanism.

The modified structure involving the present invention is in upper portion and above the hammers and their operating mechanism.

In the manufacture of a piano involving the present invention the outside casing will be of such height as to leave clear the beam-like pinblock while in applying the invention to the conventional upright piano, the case will be removed down to about the bottom of the pin block.

The invention consists in adding to this construction an auxiliary sounding board which is acted upon not only by the sound waves, but by the strings themselves.

As indicated in Figure 5, the auxiliary sound board 20 has fixed to its back surface one or more ribs 2| which are pressed tightly against the pressure bar or bars 22 carried by the pin block 23, the strings 24 secured to the tuning pins or pegs 25 passing under the pressure bar and over the bridge 26 as in the conventional construction.

The board 20 is of course of suitable resonant material and is supported upon the board 30 forming the front portion of the casing top. In front of the board 20 is a facing member 3|, which for appearance may be a mirror. This is supported at its ends by the board 30 and spaced from the sound board 20 by a rim of felt 32 along the top and two sides, and is fixed to the board 20 by suitable screws 33. The assembl of board 20, felt 32 and member 3| is fixed to the pin block 23 by suitable screws 34 which are fixed in the pin block and have their heads detachably secured to the board 20. v

The space between board 20 and member 3| is permitted communication with the outside by grooving the casing top board 30 so as to provide a groove 35 sufficiently wide to be open to the space and open to the outside in front of the member 3|. It is also desirable to provide a slot 40 or plurality thereof extending through the board in the bottom of the groove at that end of the groove 35 near which the pressure bar 22 lies at the bottom of the pin block. Further, in order to provide further sound passage into the space between the board 20 and facing member 3|, a plurality of openings may be provided in the board 20 as indicated at 4|.

Now having described the invention and the preferred embodiment thereof, it is to be understood that said invention is to be limited, not to the specific details herein set forth, but only by the scope of the claims which follow:

I claim:

1. In piano construction, a pin block, a pressure bar carried thereon and an auxiliar sounding board in contact with said bar.

2. In piano construction, a pin block, a pressure bar thereon, and a sounding board, said board being provided with a rib conforming to the shape of said bar and in contact therewith.

3. In piano construction, a pin block, a pressure bar thereon, a sounding board fixed in contact with said bar and a facing member of substantially the same area as said board mounted parallel with and in spaced relation to said board.

4. In piano construction, a pin block, a pressure .bar carried thereby, a sounding board in contact with said bar, a facing member supported by said board and arranged in parallel but spaced relation thereto and means providing communication between said space and the outside of said piano.

5. In upright piano construction, a pin block, a, main casing for said piano, said casing extending from the lower portion of the piano to about the level of the lower edge of said pin block, a casing portion surmounting said main casing and enclosing said pin block, and an auxiliar sounding board in said surmounting casing.

6. In upright piano construction, a pin block provided with a pressure bar, a main casing for said piano, said casing extending from the lower portion of the piano to about the level of the lower edge of said pin block, a casing portion surmounting said main casing and enclosing said pin block, and an auxiliar sounding board in said surmounting casing contacting said pressure bar.

JOHN W. BETHUNE. 

